Computer Networks

HNBGU BCA Previous Question Paper 2017-18

Section A

What is topology? Differentiate between any two on the basis of various parameters.
Differentiate between OSI model and TCP/IP model.
Explain IP4 diagram.
A noiseless 4KHz channel is sampled every 1m/sec. What is maximum data rate?
Data link protocols almost always put the CRC in trailer rather in header. Why?
Sketch the Manchester encoding for the bit stream 0001110101
If the TCP round trip time, RTT, is currently 30m/sec and the following acknowledgement come in after 26, 32 and 24m/sec, respectively. What is new RTT estimate? Use =0.9

Section B

1. Write short notes on the following
  1. Twisted pair cable
  2. Coaxial cable
2. What do you understand by transmission impairment? Explain three major problems.
1. Write short notes on the following:
  1. PCM
  2. QAM
2. Differentiate between circuit switching, packet switching and message switching.
1. What do you understand by bit stuffing? Explain its algorithm. If the bit string 0111101111101111110 is bit stuffed, what is the output string?
2. Explain layers of X.25
1. Consider the following sequences of frame transmission from sender to receiver:
  1. Frame 0, frame 1 is sent; both acknowledged
  2. Frame 2, frame 3, frame 4 sent, frame 2 acknowledged NAK 3 sent to sender.
  3. Frame 5, frame6, frame 7 are sent.
2. write short notes on the following:
  1. FDDI
  2. Fast Ethernet
1. Define Routing. Which later is responsible for this task? Explain the Hierarchical Routing
2. What do you understand by congestion? Explain various congestion control policies.
1. Explain TCP connection management.
2. Write short notes on the following.
  1. FTP
  2. SMTP